The invention relates to an apparatus and a method for stitching a leading end of a tire component to a trailing end of the same or another tire component along a splice line.
U.S. Pat. No. 5,348,600 discloses a method and an apparatus in which a first belt-shaped member is wound around a forming drum and subsequently a second belt-shaped member is wound around the first belt-shaped member at the forming drum. The leading end and the trailing end of each belt-shaped member are joined by butt-splicing. The uncured rubber of both belt-shaped members strongly adhere to each other at contact. To prevent the second belt-shaped member from adhering to the first belt-shaped member at the butt-line prior to joining, the leading end and the trailing end thereof are received on the sides of an auxiliary bar in the form of a triangular prism. Gripping pawls are inserted between the auxiliary bar and the respective leading end and trailing end to grip the leading end and the trailing end at multiple spaced apart positions along the leading end and the trailing end. The leading end and the trailing end are subsequently lifted from the auxiliary bar and the latter is removed in an upward direction. The leading end and the trailing end may now be brought together into butting contact by the gripping pawls.
When using these gripping pawls to move the leading and trailing end to butt against each other, the leading and trailing end of the belt-shaped member undulate along the butt line. A drawback of the known method and apparatus is therefore that at some positions along the butt line the leading end and the trailing end overlap, while at other positions along said butt line the leading end and the trailing end are at a distance from each other. Although the leading and trailing ends of the belt-shaped member can be joined by a joining roller to form a cylindrical member, the resulting joint is not of a constant quality along the butt line.
It is an object of the present invention to provide an apparatus and a method for stitching a leading end of a tire component to a trailing end of the same or another tire component along a splice line, wherein the quality of the splice can be improved.